#include <iostream>
using namespace std;

int main()
{
    int a[100005];
    int n;
    long long cost = 0;
    int fu = 0, zero = 0; // 正,负,0
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        cin >> a[i];
    }
    // 计算正负数个数
    for (int i = 0; i < n; i++)
    {

        if (a[i] < 0)
            fu++;
        if (a[i] == 0)
        {
            zero = 1;
        }
    }
    for (int i = 0; i < n; i++)
    {
        if (a[i] > 1)
            cost += a[i] - 1;
        else if (a[i] < -1)
            cost += -1 - a[i];

        else if (a[i] == 0)
            cost += 1;
    }

    if (fu % 2 != 0 && zero == 0)
    {
        cost = cost + 2;
    }

    cout << cost << endl;
    return 0;
}


/*
此代码
·在VJ提交超时---“Time limit exceeded on test 7”
·在洛谷提交AC
原因未知......

#include <iostream>
#include <algorithm>
using namespace std;
int a[100005];
int n;
long long cost = 0;
void operate()
{
    for (int i = 0; i < n; i++)
    {
        while (a[i] > 1)
        {
            a[i]--;
            cost++;
        }
        while (a[i] < -1)
        {
            a[i]++;
            cost++;
        }
        while (a[i] == 0) // a[i]为0
        {
            a[i] += 1;
            cost++;
        }
    }
}

int main()
{
    int zheng = 0, fu = 0, zero = 0; // 正,负,0
    cin >> n;
    for (int i = 0; i < n; i++)
    {
        cin >> a[i];
    }
    // 计算正负数个数
    for (int i = 0; i < n; i++)
    {
        if (a[i] > 0)
        {
            zheng++;
        }
        else if (a[i] < 0)
        {
            fu++;
        }
        else
            zero++;
    }
    // 算
    if (zero != 0) // 有0
    {
        if (fu % 2 == 0) // 偶数个负数
        {
            operate();
        }
        else // 奇数个负数
        {
            for (int i=0; i < n; i++)
            {
                if (a[i] == 0)
                {
                    a[i] = -1;
                    cost++;
                    break;
                }
            }
            operate();
        }
    }
    else // 没0
    {
        if (fu % 2 == 0) // 偶数个负数
        {
            operate();
        }
        else // 奇数个负数
        {
            operate();
            for (int i=0; i < n; i++)
            {
                if (a[i] == -1)
                {
                    cost+=2;
                    break;
                }
            }
        }
    }

    cout << cost << endl;
    return 0;
}

*/
